Command over the U.S. Armed Forces is established in the Constitution. The sole power of command is vested in the President by Article II as Commander-in-Chief. The Constitution presumes the existence of "executive Departments" headed by "principal officers", whose appointment mechanism is provided for in the Appointments Clause. This allowance in the Constitution formed the basis for creation of the Department of Defense in 1947 by the National Security Act. The DoD is headed by the Secretary of Defense, who is a civilian and member of the Cabinet. The Defense Secretary is second in the U.S. Armed Forces chain of command, with the exception of the Coast Guard, which is under the Secretary of Homeland Security, and is just below the President and serves as the principal assistant to the President in all defense-related matters. Together, the President and the Secretary of Defense comprise the National Command Authority, which by law is the ultimate lawful source of military orders.
The ASVAB is a timed test that measures your skills in a number of different areas. You complete questions that reveal your skills in paragraph comprehension, word knowledge, arithmetic reasoning and mathematics knowledge. These are basic skills that you will need as a member of the U.S. military. The score you receive on the ASVAB is factored into your Armed Forces Qualifying Test (AFQT) score. This score is used to figure out whether you qualify to enlist in the armed services.
Personnel may be recruited or conscripted, depending on the system chosen by the state. Most military personnel are males; the minority proportion of female personnel varyies internationally (approximately 3% in India, 10% in the UK, 13% in Sweden, 16% in the US, and 27% in South Africa). While two-thirds of states now recruit or conscript only adults, as of 2017 50 states still relied partly on children under the age of 18 (usually aged 16 or 17) to staff their armed forces.
It's important to understand the difference between the ASVAB Standard Scores, and the ASVAB AFQT score. Test takers will receive a separate score for each of the nine sections on the ASVAB. These scores are known as Standard Scores. A Standard Score is used to determine how the test taker compares to the "average" 18-23 year old American on that part of the ASVAB. Not long ago, a large number of people in this age group were given the tests, and these results are the benchmark for Standard Scores. Around half the people in this age group will score a 50 or higher, and about 16% will score a 60 or higher. In other words, the scoring is based on a standard bell curve distribution. Standard Scores are very important when it comes to determining which military job a person will be assigned to.